Voltage surges created by lightning strikes and longer duration over-voltages experienced on a power distribution grid can result in significant damage to electronic equipment. Where a sustained overvoltage is severe, fires have been started resulting in significant loss of property. Existing surge protection devices, such as Transient Voltage Surge Suppressors (TVSS), are typically designed to handle short duration transients of 8-20 microseconds associated with lightning strikes. As a result, TVSS devices typically provide no protection against longer duration over-voltage disturbances, and can often be the cause of the fires and damage to equipment that have been reported.